I think everyone undestood that a worn biner may break at a lower force.

I think for many people it is new infromation that a worn biner may cut a rope. That may be rare, but significantly increases the risk of a worn biner (since in many situations, biner is not the single point of failure anyway, while the rope always is).

New data --> new decisionmaking input for future climbing.

What's the big controversy for you here, besides the usual sport-vs-trad "West Side Story"-style nonsense?

Someone else corrected me well enough. That it loads the major axis more, rather than "stronger". I was just pointing out it was the sharp edge rather that the worn biner. Granted the two are not interchangeable.

I have seen a few belay devices get pretty sharp as well, and that is what too look for in worn gear, the sharp edges.

I think everyone undestood that a worn biner may break at a lower force.

I think for many people it is new infromation that a worn biner may cut a rope. That may be rare, but significantly increases the risk of a worn biner (since in many situations, biner is not the single point of failure anyway, while the rope always is).

New data --> new decisionmaking input for future climbing.

What's the big controversy for you here, besides the usual sport-vs-trad "West Side Story"-style nonsense?

+1

I think most climbers understood that a worn 'biner could DAMAGE the rope -- e.g. cause a core shot. I have heard of such incidences, of course.

And in fact this has happened to one of my ropes. Someone else was climbing on it, took a fall on a fixed 'biner, and the rope got an obvious damage in the spot that was in contact with the 'biner, the core was visibly damaged and the rope was retired, of course. (The 'biner in question was not visibly grooved or worn, by the way, though on very close inspection it looked like someone had used it as a bolt-end 'biner at some point-- still, we are not talking burrs, we are talking shallow scratches that did not feel at all sharp when running a finger over them.)

A core-damaged rope is bad news, of course, and shouldn't be climbed on, but in the above-mentioned scenario the climber was safely lowered to the ground on that rope.

I was willing to assume that under other circumstances (burred biner, for example) the rope could be damaged even more severely -- the sheath could be completely stripped, and several of the core filaments could be completely severed, for example. I've seen rope damage like that.

But no one I personally know, and myself included, has given much thought to the possibility of the rope severing completely by a carabiner. Severed by sharp rock--yes. But the 'biner, even a grooved one, still appears quite smooth.

So while the grooved 'biner was a reason for concern, the main issue, until this incident, was (at least in my head) the decreased strength of the 'biner. NOT the possibility of the rope completely cutting by the 'biner under a normal fall scenario. And yes, I have clipped a few worn 'biners myself, and climbed above them.

Now that we are aware of this, climbers would be, hopefully, more proactive in replacing the worn biners at an earlier stage of wear.

But it is a decision everyone makes: O.K., I'm halfway up the route, and there is a worn 'biner... or a rattly sling. How badly worn? Trust it, or not? We do not have a manual and calipers that would allow us to measure that wear and make an informed decision based on something solid. It is a gut feeling and experience. Sometimes we do trust it, and sometimes we decide that the damage is above the mental threshold and we should go in direct and replace it, instead of continuing the climb.

A lot of worn 'biners were taken off the overhanging routes in Muir Valley this past Saturday. I hope someone posts the pictures of them. Quite a few were very scary, indeed.

The Red River Gorge climbing community does its best to maintain and replace legitimate fixed anchors. That costs money folks. The work at Muir Valley was made possible, in part, by a very generous donation of ClimbTech PermaDraw sets from Hoosier Heights Gym in Bloomington Indiana. Some pictures of other worn gear that has been maintained / replaced @ RRG can be seen at - http://teamsuckclimbing.com/photos.php. The Team Suck site also maintains a page to report bad bolts - http://teamsuckclimbing.com/bolts.php - and to make donations to their bolt rplacement fund - http://teamsuckclimbing.com/donate.php.

The Red River Gorge climbing community does its best to maintain and replace legitimate fixed anchors. That costs money folks. The work at Muir Valley was made possible, in part, by a very generous donation of ClimbTech PermaDraw sets from Hoosier Heights Gym in Bloomington Indiana. Some pictures of other worn gear that has been maintained / replaced @ RRG can be seen at - http://teamsuckclimbing.com/photos.php. The Team Suck site also maintains a page to report bad bolts - http://teamsuckclimbing.com/bolts.php - and to make donations to their bolt rplacement fund - http://teamsuckclimbing.com/donate.php.

You cats do an awesome job on wat is likely to be a never-ending task. Hope to see of you at the AF summit at the New this weekend!

The linked BD article applies only to coldshuts. The failure mode for an ungrooved cold shut is such that as the tension in the rope increases, the rope slides toward the unanchored end of the shut, applying additional leverage, which causes the shut to bend and open, allowing the rope to slide yet farther toward the end, causing the shut to open farther, etc.

The groove in a worn shut traps the rope and doesn't allow the rope to slide, and hence, doesn't allow the additional leverage and bending.

The failure mode of a closed carabiner is different and a groove most likely serves only to lessen the ultimate breaking strength of the carabiner.

The linked BD article applies only to coldshuts. The failure mode for an ungrooved cold shut is such that as the tension in the rope increases, the rope slides toward the unanchored end of the shut, applying additional leverage, which causes the shut to bend and open, allowing the rope to slide yet farther toward the end, causing the shut to open farther, etc.

The groove in a worn shut traps the rope and doesn't allow the rope to slide, and hence, doesn't allow the additional leverage and bending.

The failure mode of a closed carabiner is different and a groove most likely serves only to lessen the ultimate breaking strength of the carabiner.

True. However, I suspect that some of us extrapolated from the results to carabiners, especially since they, too, are frequently used at anchors.

The failure mode of a closed carabiner is different and a groove most likely serves only to lessen the ultimate breaking strength of the carabiner.

I don't think that it is a forgone conclusion that a moderately grooved carabiner is weaker than an an ungrooved one. Limited information from BD suggests that the point where the groove develops, the bottom of the carabiner's basket, is not where carabiners typically break in any common failure mode. So moderate weakening there may have no effect on the biner's ultimate strength. Of course, BD presents limited data on a single model of carabiner, so we should be careful about drawing hasty conclusions from it or generalizing it to other models of carabiner.

That is misleading, as the groove serves to keep the rope at the biner's/shut's strongest point, even though it has been weakened.

The biner/shut is NOT stronger, as less metal equals less strength for two pieces of identical design. Period.

Example:

Would you rap off of a bush/tree that was 1" in diameter, strongly rooted, with a small groove worn into it at the base that was opposite the direction of force, if the load (rope) was just a few inches above the base/groove? Hell no!

BUT, if the rope was in the groove, keeping it at the base, it would likely still be hella strong.

Point... The base of the tree/bush is akin to the strongest point in the biner, and even though there is a groove, it is still string enough (if the load is applied in the right place), BUT NOT AS STRONG as if there were no groove IF the load were applied outside that groove, it would be WEAKER. And where would the biner fail? At the weakest point, where significant metal loss has weakened it (I.e., the groove)

That is misleading, as the groove serves to keep the rope at the biner's/shut's strongest point, even though it has been weakened.

The biner/shut is NOT stronger, as less metal equals less strength for two pieces of identical design. Period.

Example:

Would you rap off of a bush/tree that was 1" in diameter, strongly rooted, with a small groove worn into it at the base that was opposite the direction of force, if the load (rope) was just a few inches above the base/groove? Hell no!

BUT, if the rope was in the groove, keeping it at the base, it would likely still be hella strong.

Point... The base of the tree/bush is akin to the strongest point in the biner, and even though there is a groove, it is still string enough, BUT NOT AS STRONG as if there were no groove IF the load were applied outside that groove, it would be WEAKER. And where would the biner fail? At the weakest point, where significant metal loss has weakened it (I.e., the groove)

By that logic, a biner is only as strong as it's cross-loading strength.

It's difficult to generalize and not worth the effort. A worn biner is a worn biner. The rope might stay in the groove better and be fine. It might crossload and fail catastrophically.

The point of this whole thread is that there is a new failure mechanism that most wouldn't be aware of and that is the rare case of a knife edge wearing into biners under very special circumstances. Sport climbers should be aware.

The Squamish Access Society is currently replacing a lot of fixed hardware including draws at our most popular sport climbing area. There is a thread on our message board where people post reports of suspect gear and anchors and as well they can report it to the access society directly. IMO the community chooses where to put fixed gear and how to maintain it. There's not much more to it.

That is misleading, as the groove serves to keep the rope at the biner's/shut's strongest point, even though it has been weakened.

The biner/shut is NOT stronger, as less metal equals less strength for two pieces of identical design. Period.

Example:

Would you rap off of a bush/tree that was 1" in diameter, strongly rooted, with a small groove worn into it at the base that was opposite the direction of force, if the load (rope) was just a few inches above the base/groove? Hell no!

BUT, if the rope was in the groove, keeping it at the base, it would likely still be hella strong.

Point... The base of the tree/bush is akin to the strongest point in the biner, and even though there is a groove, it is still string enough (if the load is applied in the right place), BUT NOT AS STRONG as if there were no groove IF the load were applied outside that groove, it would be WEAKER. And where would the biner fail? At the weakest point, where significant metal loss has weakened it (I.e., the groove)

I think everyone gets the argument in semantics from the first page. Stronger was never the correct term to use. Now, the question of whether or not a biner loaded closer to its spine will break at higher loads is not definitively proven. The fact that many manufacturers are starting to incorporate indentions in newer biner designs very similar to those exhibited in rope wear spots provides at least some anecdotal evidence that biner wear to a certain extent shouldn't be a significant concern in terms of the biner breaking when loaded in a normal fall.